- Marie de Médicis, Queen, consort of Henry IV, King of France, 1573-16421
- Marriage (Roman law)1
- Martial1
- Martini, Luca, 1980-1
- Martyrologies1
- Martyrs1
- Mary, Queen of Scots, 1542-15871
- Masorah1
- Massachusetts--Northampton1
- Massacre of the Holy Innocents in art1
- Masses1
- Masses, Unaccompanied1
- Mathematical recreations1
- Mathematics, Greek1
- Mathematics, Jewish1
- Maurice, Saint, -approximately 2871
- Maximian, Emperor of Rome, approximately 240-3101
- Maximus, of Turin, Saint, active 4th century-5th century1
- Medici, Alessandro de', 1510-15371
- Medici, Bernardo d'Alamanno de'1